Title
Amdahl's law in the era of process variation
Abstract
In this paper we propose to extend Amdahl's law for modelling multicores with process variation using simple mathematical techniques. We consider three major families of multicore processors - symmetric, asymmetric, and dynamic. We consider a conservative operating mode for setting the target frequency plain, and a more optimised method opt. Subsequently, we propose three separate corollaries to the standard Amdahl's law to model the performance of different multicore configurations with different modes of operation. We observe that most of the major trends published in prior work or the ones that we observe through Monte Carlo simulations can be explained by a simple hypothetical concept called an equivalent core. The crux of our approach is to look at a set of equivalent cores with no variation that have the same performance as the target system. It is much simpler and much more intuitive to reason in terms of equivalent cores. Along with being an effective analytical tool, it can be used to speed up a lot of heuristics, and can be exposed to higher level software for advanced scheduling decisions. Lastly, we validate our models with experiments on a real system, and the maximum error is limited to 8%.
Year
DOI
Venue
2013
10.1504/IJHPSA.2013.058984
IJHPSA
Keywords
Field
DocType
simple hypothetical concept,real system,simple mathematical technique,process variation,different multicore configuration,multicore processor,major trend,major family,different mode,equivalent core,amdahl s law
Monte Carlo method,Amdahl's law,Computer science,Scheduling (computing),Parallel computing,Algorithm,Heuristics,Process variation,Multi-core processor,Karp–Flatt metric,Speedup
Journal
Volume
Issue
Citations 
4
4
1
PageRank 
References 
Authors
0.36
16
4
Name
Order
Citations
PageRank
Gayathri Ananthanarayanan121.07
Geetika Malhotra210.36
M. Balakrishnan351872.63
Smruti R. Sarangi444741.94